The only remaining doubt about Iowa running back Shonn Greene centered on whether he could maintain his extraordinary consistency against an elite team.

Consider that question answered.

Greene ran for 117 yards and two touchdowns on 28 carries Saturday in the Hawkeyes' 24-23 victory over previously unbeaten Penn State. The performance made Greene the new No. 1 running back in the Rivals.com College Football Power Rankings, which measure the nation's top players and coaches at each position.

"Every game we play is physical," Greene said. "This is the Big Ten, and you're going to have physical games week in and week out. They [Penn State] have a great defense and they did a good job, but we came to play."

Greene has run for 1,374 yards this year and ranks third in the nation behind Michigan State's Javon Ringer and Connecticut's Donald Brown. Greene has averaged more yards per carry (6.1) than either Brown or Ringer, and he also has rushed for at least 100 yards in each of the Hawkeyes' nine games this season.

"Shonn has been banged around," Iowa coach Kirk Ferentz said. "He'll get banged around here the next two weeks, but he keeps coming back. [The Penn State game] was just a phenomenal effort on his part, and that's nine … games now where he's the same guy every week. He just comes and plays. It serves as a real example to our whole team. He makes everybody a little bit better."

Iowa's victory also caused Penn State's Tom Bradley to lose his spot as the No. 1 defensive coordinator in the power rankings. Bradley was replaced by USCs Nick Holt, whose team continues to lead the nation in total defense and scoring defense after a 17-3 victory over California.

Florida State kicker Graham Gano replaced Utah kicker/punter Louie Sakoda as the nation's No. 1 special teams player. Gano has made 17 consecutive field-goal attempts, including five from at least 50 yards. He made kicks from 37 and 52 yards and also averaged 41.3 yards per punt Saturday in a 41-27 victory over Clemson.

The rating of a player and coach can fluctuate each week during the season depending on how they fared the previous week, but the power rankings measure overall career performances as well as their most recent results.